Synergists to aerosol insecticides



Patented Apr. 4, 1944 SYNEBGISTS T AEROSOL IN SEGTICIDES William N.Sullivan, Washington,

odhue, Berwyu, United States of Am Claude R. Wickard,

D. Go

1941, Serial No.

D. 0., and Lyle Md., assignors to the cries. as represented by Secretaryof Agriculture, and his successors in oillce No Drawing. Originalapplication September 30,

412,960. Divided "and this application January "I, 1944, Serial No.517,372

3 Claims. (Cl. 167-22) (Granted lllldel' the act of March 3, amendedApril 30, 1928; 370 0. G.

This application is made under the act of March 3, 1883, as amended bythe act of April 30, 1928, and the invention herein described andclaimed. it patented, may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment to us of any royalty thereon. I

This is a division of our copendlng application for patent, Serial No.412,960, filed September 30, 1941.

Our invention relates to materials which will increase the effectivenessof insecticides in aerosol form.

Certain agents which may or may not be toxic in themselves when added toaerosol insecticides greatly increase the rate of. mortality. Theincreased toxicity obtained by the combination of such materials isoften referred to as .synergism" and the added material a synergist.

Therefore, in these terms, the general object of our invention is theprovision of materials suitable as synerglsts for aerosol insecticides.

Another object of our invention is the provision of agents which willnot only increase the insecticidal action of materials known to possesssome toxicity, but, which will also impart insecticidal properties tomaterials which are known to be non-toxic or to have a very lowtoxicity.

A further object of our invention is the provision of such agents actingas synergists, which can be applied by dispersion simultaneously withand by the same methods used for the preparation of aerosolinsecticides.

We have found that materials suitable for the purposes of this inventionbelong most 1 frequently to the class of chemical compounds which aresurface active in non-aqueous solvents or which act as detergents innon-aqueous solvents. These compounds, in general, contain polargroupings such as the hydroxyl, the carboxyl, the amine, the ammonium,or the sulfonic acid, alone, in multiple, or in combination, which isattached to some long chain aliphatic radical, or, in some cases, anaromatic radical.

Substances acting asdetergents or surface active agents in non-aqueousmedia can be easily applied by the usual methods of aerosol production,but this invention is not limited to these substances because differentmethods of aerosol when mixed production can be used with differenttypes of synergists. In this class of chemical compounds we have foundthe fatty acids, the .mono esters of fatty acids and ethylene orpropylene glycol of glycerine or sorbitol, as well as fatty acids incombination with amines such as methanolamine, sulfonated aryl and,alkyl radicals alone or combined with an amine. There are many processeswhich can be used to apply these materials in the form of aerosols, suchas spraying into the atmosphere, vaporization, by chemical reaction, byspraying on a heated surface, and so forth. Although this invention' isnot limited to any particular method of applicatiom our preferred methodof application comprises dissolving thesynergist in the insecticide, ifthe insecticid is a liquid, or dissolvingit in some solvent common toboth if a solid, and spraying the solution on a heated surface, wherebyan aeroso] is formed composed of both the synergist and the insecticide.

A synergist to an insecticide in aerosol form is not necessarily also asynergist to an insecticide in spray form, even of the same compound..Actual tests have disclosed that an agent which possesses little or noeffect as a synergist to an insecticidal spray may be extremelyeffective as a synergist to an insecticidal aerosol. The reason for thisis not apparent, but it would seem that the mere wetting of the insectcannot explain the action.

The following results were obtained using synergists in accordance withthis invention. These results were obtained on the basis of preliminarytests first carried out in a small chamber of 7 cu. ft. and then on alarger scale in a 216 cu. ft. chamber. In each test from 500 to 600flies were used. Six-tenth of a pound of o-dichlorobenzene per 1000 cu.ft. gave only a 2% kill. However,

with 0.16 lb. of oleic acid as a synergist, a kill was obtained. Thissame quantity of oleic acid, when used alone under the same conditionsgave only a 1% kill. Lauric acid when used alone in the same amount,namely, 0.16 lb. per 1000 cu. ft., gave only a 1% kill, but when used asa synergist with 0.6 lb. or o-dichlorobenzene per 1000 cu. ft. a killwas obtained.

The same synergists were tested at other conto be especially suitablecentrations and it was found that little is gained by adding more thanThe following is a list of substances which were tested as synergists ata concentration of 0.06 lb.

in 0.6 lb. of o-dichlorobenzene per 1000 cu. ft. against the housefly,the percentage of kill in each case being indicated in the right handcolumn:

Other insecticides were used against the American and German cockroachat a concentration of 1.5 lbs. per 1000 cu. ft. One-tenth of theinsecticide was replaced by a synergist.- A mortality of 100% wasobtained with the following: methyl chloroacetate plus lauric acid,epichlorohydrin plus Iauric acid, epichlorohydrin plus oleic acid, ethyldichloroacetate plus lauric acid, ethyl dichloroacetate plus oleic acid,beta-chloroethyl chlorocarbonate plus lauric acid,beta-chloroethylacetate plus lauric acid, tetrachloroethane plus lauricacid, and o-dichlorobenzene plus lauric acid. In all cases where oleicacid was effective, lauric acid was also found to be effective and viceversa. The kill without a synergist was always less than 100% andusually less than In a 1100 cu. ft. room, naturally infested withcockroaches, more than 5000 were killed in 18 hours and none were foundliving, using 1% lbs. of o-dichlorobenzene with 3% lauric acid and 2%oleic acid. Excellent results were also ob tained ina 3200 cu. ft. room.1

Tests were also conducted against the carpet beetle larva, the confusedflour beetles and crisis ets. The halogenated esters in combination withany One of the synergists mentioned above are extremely toxic to theconfused flour beetle and produce a high mortality to the carpet beetlelarva. 1

AmongBO compounds tested against the house: fly in the form of aerosols,in combination with synergis'ts of the type mentioned. above, are 3-chloroacenaphthene, 2-chlorofluorene, 3-chioro= dibenzofuran,chlorinated diphenyls, halogenated naphthalenes, halogenated esters,halogenated ketones, carbazole, thiocresol and halogenated phenols. Thesynergist was shown to be responsible in each case for anincrease intoxicity.

Having thus described our invention, we claim:

1. An insecticide in aerosol form comprising oleic acid and thiocresol.

2. An insecticide in aerosol form comprising lauric acid and thiocresol.

3. An insecticide in aerosol form comprising triethanolamine oleate andan agent chosen from the group consisting of methyl chloroacetate, ethyldichloroacetate, beta-chloroethyl chlorocarbonate, andbeta-chloroethylacetate.

WILLIAM N. SULLIVAN. LYLE D. GOODHUE.

